"There's been a weird backlash among, I presume, fairly stupid people about the fact the shows are complicated and clever, but they're both huge international hits," the 50-year-old told BAFTA Guru.

"We make no apology. Don't expect to do the ironing; sit down, pay attention and think about it. Audiences like complexity.

"They follow intricately plotted soap operas all the time. It depresses me when people say, 'It's all far too clever'."

On not having any plans to move on from the two programs, he added: "The moment it's time to stop on a show is not an ambiguous feeling - you just suddenly think, 'I can't do it anymore; I've had enough'."